As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RETURNED TO ATL DUE TO A REPORT OF A BURNING ODOR IN THE CABIN. NO VISIBLE SMOKE SEEN WITH LIGHTS OFF, STILL HAD ODOR IN CABIN. PERFORMED OPN 5088. FOUND HYDRAULIC LEAK FROM RT T/R CONTROL VALVE LINE. TORQUED SAME AND CLEANED APU INLET. PERFORMED OPN 5090 ALTERNATE DUCT BURNOUT. LEAK AND OPS CHECK GOOD.